Resp. Infection

Unfortunately my birds have contracted a resp. infection. I got some chickens over a month ago and a few weeks later one got sick. He was sneezing and gergling and had discharge from his nasal passages that smelled. Now slowly everyone is getting it. I wish i could go back in time and decided not to get those chickens. My turkeys are my biggest concern. They are so much more sensitive to things then chickens. you know the saying the bigger they are the harder they fall. Anywho i have found that they have Infectious Sinusitis. I've read many different antibiotics to give and that injectable is best since it affects the respiratory system. Which antibiotic is best? They rattle off so many different kinds i just dont know which to pick. Tylosin seems to be the only one i can find over the internet. Is there a prescription antibiotic that works best? How much should i give each bird and for how long? I have Bourbon Red turkeys, mixed chickens and runner ducks that all run around the same patch of land, housed in 3 seperate building and each group is showing signs except for the ducks. Should i treat every bird ( that would be about 35 total). I'd ask my vet these questions but i think you guys would all know better from experience, i dont think he has delt with much poutry but he will get me a prescription if i need one. Thanks so much for and info you all can give me.

Thanks for the link. I did read injectables could damage the muscles but water soluble antibiotics wouldnt work for infections that have affected the respiratory system but i'm all for getting my birds better so i will read more on the antibiotic that you suggested!